One vertex per element, one color per generator, with an edge from x to x·s.
(9,10,15,19)(11,16,14,24)(12,13,18,17)(20,22,21,23)(25,26,31,29)(27,34,33,30)(28,36,38,32)(35,37,39,40)(1,2)(3,5)(4,6)(7,8)(9,11,15,14)(10,16,19,24)(12,21,18,20)(13,23,17,22)(26,29)(27,33)(32,36)(35,39)(1,2,4,6)(3,7,8,5)(9,12,15,18)(10,17,19,13)(11,20,14,21)(16,23,24,22)(25,27)(26,30)(28,35)(29,34)(31,33)(32,37)(36,40)(38,39)(1,3,4,8)(2,5,6,7)(9,12)(10,13)(11,21)(14,20)(15,18)(16,23)(17,19)(22,24)(25,28)(26,32)(27,35)(29,36)(30,37)(31,38)(33,39)(34,40)(1,3)(2,5)(4,8)(6,7)(9,13)(10,18)(11,22)(12,19)(14,23)(15,17)(16,21)(20,24)(25,29,31,26)(27,34,33,30)(28,36,38,32)(35,40,39,37)(1,2)(3,5)(4,6)(7,8)(9,14,15,11)(10,16,19,24)(12,20,18,21)(13,23,17,22)(25,30,31,34)(26,33,29,27)(28,37,38,40)(32,39,36,35)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.